Combined cooling coil and defrosting assembly for refrigerators



Dec. 3, 1957 H. c. RHODES 2,

COMBINED COOLING COIL AND DEFROSTING ASSEMBLY FOR REFRIGERATORS Filed Feb. 15, 1955 2 Sheets-Sheet l INVENTOR. HERBERT c. RHODES E BY ATTORNEY Dec. 3, 1957 H. c. RHODES 2,814,934

COMBINED COOLING con. AND DEFROSTING ASSEMBLY FOR REFRIGERATORS Filed Feb. 15, 1955 2 Sheets-Sheet 2 INVENTOR. HERBERT RHODES AT TOR N EY United States Patent 2,814,934 COMBINED COOLING COIL AND DEFROSTING ASSEMBLY FOR REFRIGERATORS Herbert C. Rhodes, Portland, Oreg. Application February 15, 1955, Serial No. 488,231 4 Claims. (Cl. 62-126) This invention relates in general to refrigerators of various types in which the cooling or refrigerating is accomplished in the customary manner by means of the circulation of a refrigerant through a cooling coil located inside the refrigerator.

As is well known, the condensation on the cooling coils, of moisture evaporating from foods and other products placed in a refrigerator, and in particular, condensation'of moisture in the outside air which is admitted to'the refrigerating or cooling chamber of a refrigerator every time the door of the refrigerator is opened, builds up in the form of frost or ice on the cooling coils and necessitates the frequent defrosting of the cooling coils for the removal of such frost or ice from the coils, since otherwise such coating on the coils would act as partial insulation and would increasingly reduce the effectiveness of the coils.

An object of the present invention is to provide an improved cooling coil assembly for refrigerators in which the defrosting can be accomplished more quickly and more efficiently.

During the defrosting of the cooling coils in a refrigerator the circulation of refrigerant through the coils has to cease and thus the cooling or refrigeration is entirely halted temporarily. Consequently, many modern refrigerators provide heating means adjacent the cooling coils solely for the purpose of speeding up the time required for .defrosting the coils. However, while the use of heating means in this manner does reduce the time required for the defrosting, on the other hand in some cases a considerable portion of the heat from such heating means is disseminated throughout the chamber in the refrigerator instead of being concentrated on the surfaces to be defrosted and thus the advantage in speeding up the defrosting is partly offset by more increase in the temperature within the refrigerator than should be necessary.

Anotherv object of my invention is to provide a cooling coil assembly with defrosting heating means so arranged that the resulting heat will be concentrated on the surfaces to be defrosted with only a minimum amount of heat passing beyond such surfaces.

The removal of frost or ice from the cooling coils themselves. or from other similar cylindrical surfaces, by the application of external heat, presents more of a problem than the removal of ice from a plane surface inasmuch as the external heat in the former case must be applied in several directions unless more time is consumed. An important object of this invention is to provide a cooling coil assembly so constructed and arranged that the accumulation of the frost or ice would beconfined to a pair of plane surfaces, and more particularly to vertical plane surfaces, so that no defrosting'of'o't her surfaces or of the coils themselves would be required.

A related object of the invention is to provide a combined cooling coil and defrosting assembly in which the cooling coils will be enclosed in a housing and thereby protectedfrom circulating currents of air, without, howevergany appreciable loss of the cooling efliciency of the coils in'the refrigerator.

A still further object of the invention is to provide a cooling coil and defrosting assembly which will be simpleand practical as well as eflicient, and which will be relatively inexpensive to make and install and which will require only a minimum amount of care in operation and maintenance.

The manner in which and the means by which these objects and other advantages are attained with my invention will be readily understood from the following description. In the description reference is made to the accompanying drawings, wherein:

Figure 1 is a front elevation of a familiar type of refrigerator, with a portion of the refrigerator door broken away to show my improved cooling coil and defrosting assembly mounted in place within the refrigerator;

Figure 2 is an elevation of one side of the cooling coil and defrosting assembly by itself, the view being taken from the right of the assembly of Figure 1;

Figure 3 is a similar elevation of the opposite side of the same assembly;

Figure 4 is a transverse section of the assembly taken on line 4-4 of Figures 2 and 3 drawn to a larger scale;

Figure 5 is a sectional elevation on line 55 of Figure 4, drawn to a still larger scale with a portion of the cooling coil and a portion of an inside wall of the housing broken away;

Figure 6 is a front end view the slide, constituting the front partially raised; and

Figure 7 is a plan section on line 7-7 of Figure 4.

Referring first to Figures 1-4, inclusive, my assembly includes a composite housing, designated in general by the reference character 16, which is mounted on the inside of a refrigerator, such as a refrigerator 11 shown in Figure 1, parallel to and spaced a slight distance from one of the walls of the refrigerator.

The housing 10 encloses a refrigerator cooling coil through which the refrigerant circulates and which coil is approximately equal to the size of the housing. The housing has a pair of inner side walls 12 and 13 (see Figure 4) which are vertical and parallel and which are spaced apart a distance equal to the external diameter of the tube which forms the cooling coil 14, and the cooling coil is in contact with these inner walls throughout its extent. The walls are secured together in their spaced relationship.

In the particular construction illustrated, and as shown most clearly in Figure 4, the wall 12 has a top portion 15 which is bent over at to form the top wall of the housing, and which extends over on, and is secured to, an outwardly turned flange 16 formed along the top of the other or opposite wall 13. The wall 12 also has a bottom portion 17 which extends over horizontally to the bottom portion of the wall 13, thus forming the bottom wall of the housing, and then the portion 17 is turned downwardly to abut the downward end of the wall 13. At the rear end of the housing the two walls 12 and 13 have inwardly extending flanges 18 and 19 (Figure 7) which overlap and which are secured together and thus form the rear wall of the housing. This rear wall is provided with openings for the inlet and outlet ends of the cooling coil 14.

The front ends of the walls 12 and 13 terminate in outwardly extending flanges 20 and 21, respectively (Figures 4 and 7) on which a slide 21' is mounted, which slide forms the front end wall of the housing 10. When access of the interior of the housing is desired, or when the cooling coil is to be removed from the housing for any reason, the front slide or front wall 21 can be raised to enable this to be done.

A pair of external walls or plates 22 and 23 are secured on the outer faces of the walls 12 and 13, respectively. These external walls are each formed with a continuous channel 24 and 25 respectively, to accommodate an elecof the assembly showing end wall of the housing,

Patented Dec. 3, 1957- trical heating element 24 and 25', respectively. These channels in the external walls or plates 22 and 23 face inwardly, the external walls being deformed outwardly in order to provide such channels. As shown in Figures and 7, the depth of the channels is slightly greater than the diameter of the heating elements 24' or 25. After the heating elements are placed in the channels of the respective external Walls, the remaining space in the channels is filled with thermo-mastic which will readily conduct heat and which is electrically non-conducting and which does not deteriorate under temperature changes. The resulting surfaces of the filled channels are made flush with the inside faces of their respective walls 22 and 23.

The external walls 22 and 23, with their heating elements mounted therein, are firmly secured on the respective inside walls 12 and 13 by rivets 26, or by any other suitable means, and, since the channels in the external walls are completely filled, there are no air spaces between the inside walls and their respective external walls. This is important since any air pockets or spaces would act as partial insulation and interfere with the effective transfer of cold from the cooling coil within the housing to the outer faces of the external Walls.

Thus the composite side walls of the housing are formed of double thickness of metal, but since the two layers of metal are contiguous and since the cooling coil is in contact with the housing walls throughout its extent, there is no loss in cooling eificiency as a result of the enclosing of the cooling coil entirely within the housing. Bolts 27, extending transversely throughout the housing, hold the composite walls firmly against the surfaces of the cooling coil.

The fact that the housing 10 is closed, even though it is not entirely air tight, prevents air currents from contacting the cooling coil so that there is practically no frosting of the cooling coil, the frosting occurring on the outside of the housing and thus mainly on the outside faces of the external walls 21 and 23.

The heating elements 24' and 25 are connected to a source of electric energy through the medium of a suitable control switch (not shown). When defrosting is necessary the compression motor of the refrigerator is turned off and current is turned on to the heating elements 24 and 25. Due to the distribution of the heating elements over the surfaces to be defrosted and to the close proximity of the heating elements to such surfaces, and also partly due to the fact that the surfaces are vertical and substantially plane as well as smooth, the defrosting will take place in a minimum amount of time and with very efiicient utilization of the heat required, the products of the defrosting dropping readily off the warmed vertical surfaces.

The entire housing assembly is mounted on an upwardly extended wall 28 (Figure 4) of a trough 28, and this wall 28' terminates in a downwardly turned flange 29. The lower portion of the inside walls are secured to this flange 29, as shown best in Figure 4-, by bolts 30 and interposed spacers 31. The spacers enable the water and ice particles, or the products of defrosting, from the external wall 23 to drop freely into the trough 28 the same as the water and ice particles from the wall 22. The opposite wall 32 of the trough 2% is secured to the refrigerator wall by means of brackets 33.

The wall 28 of the supporting trough may be provided with a suitable holder 34 and a shelf support 35, as shown in Figure 4, for removably supporting one side of a refrigerator shelf 36 (Figure 1).

Various minor modifications could be made in the construction which I have illustrated and described without departing from the principle of my invention, and it is not my intention to restrict my invention otherwise than is set forth in the claims.

I claim:

1. In a cooling coil and defrosting assembly of the character described, a closed housing having a pair of parallel inside walls, a cooling coil located in said housing, the spacing between said walls corresponding to the external diameter of the tube from which said coil is formed, external walls extending over the outer faces of said inside walls respectively secured to and contiguous with said inside walls, a heating element within each of said outside walls, means for mounting said housing within a refrigerator and means for receiving the products of defrosting when said housing is defrosted.

2. In a cooling coil and defrosting assembly of the character described, a closed housing having a pair of parallel inside substantially vertical walls, a cooling coil located in said housing, the spacing between said walls corresponding to the external diameter of the tube from which said coil is formed, said housing acting to exclude air currents from contact with said coil, external walls extending over the outer faces of said inside walls respectively and contiguous with said inside walls, each of said outside walls formed with an inwardly facing channel, heating elements in said channels, means combining with said heating elements for completely filling up said channels, whereby to exclude any air pockets between said corresponding inside and outside walls, and means for mounting said housing within a refrigerator.

3. In a cooling coil and defrosting assembly of the character described, a closed housing having a pair of parallel inside substantially vertical walls, a cooling coil located in said housing, the spacing between said walls corresponding to the external diameter of the tube from which said coil is formed, said housing acting to exclude air currents from contact with said coil, external walls extending over the outer faces of said inside walls respectively secured to and contiguous with said inside walls, each of said outside walls formed with an inwardly facing channel, electric heating elements located entirely within said channels, means combining with said heating elements for completely filling said channels flush with the inside face of said outside walls, whereby to exclude any air pockets between said corresponding inside and outside walls, electric conductors connected to said heating elements, and means for mounting said housing within a refrigerator.

4-. A combined cooling coil and defrosting assembly for refrigerators and the like including a closed housing having a pair of parallel inside substantially vertical walls, a cooling coil located in said housing, the spacing between said walls corresponding to the external diameter of the tube from which said coil is formed, said housing acting to exclude air currents from contact with said coil, external walls extending over the outer faces of said inside walls respectively secured to and contiguous with said inside walls, each of said outside walls formed with an inwardly facing channel, heating elements located entirely within said channels, means combining with said heating elements for completely filling said channels flush with the inside face of said outside walls, whereby to exclude any air pockets between said corresponding inside and outside walls, said housing having top, bottom, rear and front end walls, said front wall being removably mounted on said housing to permit access to the interior of said housing and to said coil, electric conductors connected to said heating elements, means for mounting said housing within a refrigerator and means for receiving the products of defrosting when said housing is defrosted.

References Cited in the file of this patent UNITED STATES PATENTS 2,410,194 Baker Oct. 29, 1946 2,492,397 Peterson Dec. 27, 1949 2,553,657 La Porte May 22, 1951 2,683,355 Schmidt July 13, 1954 2,726,515 Kleist Dec. 13, 1955 

